Derivative Instruments and Hedging Activities (Risk Disclosures) (Details) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended			3 Months Ended		6 Months Ended				6 Months Ended
	Jun. 30, 2012 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2011 USD ($)	Dec. 31, 2011 USD ($)	Jun. 30, 2012 GBP (£)	Dec. 31, 2011 GBP (£)	Jun. 30, 2012 PPL Energy Supply LLC [Member]	Jun. 30, 2011 PPL Energy Supply LLC [Member]	Jun. 30, 2012 PPL Energy Supply LLC [Member]	Jun. 30, 2011 PPL Energy Supply LLC [Member]	Jun. 30, 2012 LG And E And KU Energy LLC [Member] USD ($)	Dec. 31, 2011 LG And E And KU Energy LLC [Member] USD ($)	Jun. 30, 2012 Louisville Gas And Electric Co [Member] USD ($)	Dec. 31, 2011 Louisville Gas And Electric Co [Member] USD ($)
Interest Rate Risk - Cash Flow Hedges (Numeric) [Abstract]
Year of expiration of the maximum maturity date of interest rate cash flow hedge contracts			2023
Notional value of interest rate cash flow hedge contracts (excludes cross-currency contracts)	$ 300		$ 300
Net notional value of PPL WEM's cross-currency cash flow hedge contracts	960		960
Latest maturity date of PPL WEM cross-currency cash flow hedge contracts	2021		2021
Net notional value of PPL WW cross-currency cash flow hedge contracts	302		302
Latest maturity date of PPL WW cross-currency cash flow hedge contracts	2028		2028
Insignificant or no hedge ineffectiveness associated with interest rate cash flow hedges	insignificant		insignificant					insignificant	insignificant	insignificant	insignificant
Hedge ineffectiveness associated with interest rate cash flow hedges		(9)		(9)
Hedge ineffectiveness associated with certain interest rate swaps that failed hedge effectiveness testing		(4)
No or insignificant after-tax gains (losses) previously recorded in AOCI reclassified to earnings related to interest rate cash flow hedge contracts	no such reclassifications	no such reclassifications	no such reclassifications	no such reclassifications				no such reclassifications	no such reclassifications	no such reclassifications	no such reclassifications
Net unrealized after-tax gains (losses) on interest rate cash flow hedge contracts expected to be reclassified into earnings during next 12 months	(12)		(12)
Interest Rate Risk - Fair Value Hedges (Numeric) [Abstract]
Year of expiration of the maximum maturity date of interest rate fair value hedge contracts			2047
Notional value of interest rate fair value hedges	99		99
No or insignificant hedge ineffectiveness associated with interest rate fair value hedges	did not recognize	did not recognize	did not recognize	did not recognize				did not recognize	did not recognize	did not recognize	did not recognize
No or insignificant gains (losses) associated with interest rate fair value hedges being excluded from the assessment of hedge effectiveness	did not recognize	did not recognize	did not recognize	did not recognize				did not recognize	did not recognize	did not recognize	did not recognize
No or insignificant gain (loss) resulting from firm commitments that no longer qualified as interest rate fair value hedges	did not recognize	did not recognize	did not recognize	did not recognize				did not recognize	did not recognize	did not recognize	did not recognize
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Notional amount of interest rate swaps classified as economic activity	179		179									179		179
Year of expiration of the maximum maturity date of interest rate economic activity contracts			2033									2033		2033
The fair value, net (asset) or liability, of interest rate swap contracts classified as economic activity	62		62		60							62	60	62	60
Foreign Currency Risk - Net Investment Hedges (Numeric) [Abstract]
Notional amount of net investment hedge contracts	153		153			96
Earliest settlement date of net investment hedge contracts			September 2012
Latest settlement date of net investment hedge contracts			June 2013
Insignificant fair value of position of net investment hedge contracts			insignificant
Fair value of net asset position of net investment hedge contracts					7
Notional amount outstanding on intercompany loan qualified as a net investment hedge	43		43			28
Net after tax gains (losses) on net investment hedges recognized in the foreign currency translation adjustment component of AOCI			19		19
Insignificant or no net after tax gains (losses) on net investment hedges recognized in the foreign currency translation adjustment component of AOCI	insignificant	insignificant	insignificant	insignificant
Foreign Currency Risk - Economic Activity (Numeric) [Abstract]
Total exposure hedged related to foreign currency contracts for anticipated earnings hedges classified as economic activity						1,000	288
Fair value of net asset or (liability) position of foreign currency contracts for anticipated earnings hedges classified as economic activity	12		12		11
Earliest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity			July 2012
Latest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity			June 2014
Gains (losses) on foreign currency contracts for anticipated earnings hedges classified as economic activity	25		7
Insignificant or no gains (losses) on foreign currency contracts for anticipated earnings hedges classified as economic activity		insignificant		insignificant
Gains (losses) on foreign currency contracts related to debt or commitments hedged with foreign currency contracts classified as economic activity		$ 62		$ 55